Supreme Court nominee and woman accusing him of sex assault are expected to be called to testify at Senate panel hearing.

US Supreme Court nominee Brett Kavanaugh and Christine Blasey Ford, a woman who has accused him of sexually assaulting her in the 1980s, are expected to be called testify in a hearing of the Senate Judiciary Committee next week.

Senate leaders, under pressure from fellow Republicans who wanted a full, open examination of the allegations, announced the move late on Monday.

According to Ford, Kavanaugh groped her and tried to take off her clothes at a party when they were teenagers. Kavanaugh, who was nominated by President Donald Trump, has repeatedly denied the allegations.

After initially suggesting a private conference call on the matter would suffice, Senate Judiciary Committee Chairman Chuck Grassley said his panel would hold a hearing next Monday "to provide ample transparency".

The move forced Republicans to put off a planned committee vote for Thursday on Kavanaugh's nomination. The delay makes it increasingly difficult for Kavanaugh to win approval by October 1, when the new session of the Supreme Court begins. It also potentially sets up a public, televised airing of sexual misconduct allegations, reminiscent of the seminal hearings against Clarence Thomas in 1991, that could derail Kavanaugh's nomination altogether.

Although it was originally reported that Ford would testify, Grassley said that by Tuesday afternoon, the college professor had not responded to attempts by the judiciary committee to contact her about appearing at the hearing.

Debra Katz, Ford's lawyer, had previously said her client would be willing to testify, but had yet to comment on next Monday's hearing.

Democrats say Monday hearing is too soon

Prior to the announcement about the hearing, Republican leaders displayed no willingness to delay a Judiciary panel vote that Grassley had planned for this Thursday to advance the nomination.

But after calls mounted from politicians on both sides of the political aisle, next Monday's hearing was announced.

Democrats have called for a full FBI investigation of the allegations, however, saying the Monday hearing will be too soon.

Senator Richard Blumenthal, who is a member of the Judiciary Committee, told the Washington Post that if a hearing takes place before an investigation, "the committee is going to be shooting in the dark with questions".

"As a former prosecutor and state attorney general, there's no way I would put a crime survivor on the stand in front of a jury, let alone the American people, without a full investigation so that I know what the facts are before I start asking questions," Blumenthal told the newspaper.

Democratic Senator Patrick Leahy of Vermont echoed Blumenthal's comments in an interview with NPR, admitting an investigation may take a couple of weeks.

"What difference does one or two weeks make when you're talking about a lifetime appointment," he told the public radio broadcaster.

In a statement to local media, the Department of Justice said the "FBI does not make any judgement about the credibility or significance of any allegation".

If the Judiciary Committee's timetable slips further, it would become increasingly difficult for Republicans to schedule a vote before the November 6 elections, in which congressional control will be at stake.

With fragile GOP majorities of just 11-10 on the Judiciary Committee and 51-49 in the full Senate, Republican leaders had little room for defectors without risking a humiliating defeat of Trump's nominee to replace retired Justice Anthony Kennedy.

Trump has defended his pick, dismissing any notion that Kavanaugh's nomination should be withdrawn.

"I feel so badly for him that he's going through this, to be honest with you," Trump said on Tuesday. "This is not a man that deserves this," he told reporters.

Trump has accused Democrats of playing politics by not zeroing in on the accusation against the judge until days before the Senate Judiciary Committee was poised to vote on his nomination.

Kavanaugh has had a relatively smooth confirmation track until the allegations against him were reported last week. Ford, whose identity was unknown until Sunday, had sent a letter to Democratic Senator Dianne Feinstein in July. In the letter, Ford said she had received medical treatment after the assault, adding that "it is upsetting to discuss sexual assault and its repercussions, yet I felt guilty and compelled as a citizen about the idea of not saying anything".

After reports of the letter surfaced last week, Feinstein released a statement, saying she had received the letter".

"That individual [who sent the letter] strongly requested confidentiality, declined to come forward or press the matter further, and I have honoured that decision. I have, however, referred the matter to federal investigative authorities," Feinstein said.

According to the Washington Post, Ford, who had also contacted the newspaper in July, decided to go public after it became clear people were learning her identity.

'I've seen process weaponised against accuser'

Ford's allegations come nearly a year after the #MeToo movement was popularised following the numerous allegations of sexual misconduct by Hollywood Producer Harvey Weinstein, who has since been charged with rape and other sexual crimes. Weinstein denies the allegations.

Since then, allegations of sexual abuse have rocked numerous industries and professions including the media and political scene. According to the National Sexual Violence Resource Center, one in three women in the United States experience some form of sexual violence in their lives.

Ford's challenge also evoked the 1991 battle over the Republican nomination of Clarence Thomas, now the court's most conservative justice.

During his hearings, allegations from a former colleague, law school professor Anita Hill, surfaced accusing him of repeated sexual harassment when they worked together. Thomas denied the allegations.

Hill endured a brutal assault on her personal reputation in hearings and in conservative media and the all-male Republicans on the committee ultimately backed Thomas.

In a statement issued on Friday, Hill said: "I have seen firsthand what happens when such a process is weaponised against an accuser, and no one should have to endure that again."